Theories of Intelligence

The American Psychological Association defines intelligence as “the ability to derive information, learn from experience, adapt to the environment, understand, and correctly utilize thought and reason” (2018). However, cognitive processes are complex, and describing them in a measurable way is challenging. Researchers have taken different approaches to define intelligence in an attempt to comprehensively describe and measure it.

Charles Spearman (1863–1945) was one of the first psychologists to attempt to define, measure, and test intelligence. He observed school children and noticed that their performance in unrelated classes was positively correlated; children who did well in one class were more likely to do well in others and children who struggled in one class tended to struggle in others (Spearman, 1904). He hypothesized that there must be a single underlying construct that affects cognitive abilities called the general intelligence factor ("g") (Spearman, 1904). Many psychologists now believe that “g” relates to abstract thinking and includes the abilities to acquire knowledge, to adapt to novel situations, and to benefit from instruction and experience (Gottfredson, 1997; Sternberg, 2003). 

However, Spearman acknowledged in his work that there are other attributes, or specific intelligence factors (“s”), that contribute to intelligence (Beaujean, 2019). These can be thought of as specific skills a person has that relate to certain intelligence tasks. For example, people working in a music-related field may have “s” that improves their performance on rhythm tasks.

Cattell’s Crystallized and Fluid Intelligence

In the 1940s, Raymond Cattell proposed a theory of intelligence that divided general intelligence into two components: crystallized intelligence and fluid intelligence (Cattell, 1963). Crystallized intelligence is characterized as acquired knowledge and the ability to retrieve it. When you learn, remember, and recall information, you are using crystallized intelligence. A student often uses crystallized intelligence by demonstrating mastery of course information on an exam. Fluid intelligence encompasses the ability to see complex relationships and solve problems. Navigating your way home after being detoured onto an unfamiliar route by road construction would draw upon your fluid intelligence. Fluid intelligence helps you tackle complex, abstract challenges in your daily life, whereas crystallized intelligence helps you overcome concrete, straightforward problems (Cattell, 1963).

Sternberg’s Triarchic Theory of Intelligence

Robert Sternberg is another advocate for the idea of multiple intelligences. Sternberg’s Triarchic Theory of Intelligence suggests that intelligence has three components: analytical intelligence, practical intelligence, and creative intelligence (Sternberg, 1997). People may display varying levels of each of these types of intelligence and they are not necessarily correlated with each other.

Analytical intelligence is closely aligned with academic problem solving, which includes the ability to analyze, evaluate, judge, compare, and contrast. When students analyze a short story or solve math problems, they are using analytical intelligence. Practical intelligence can be compared to common sense learned from life experiences, not from books or formal education. Think about the choice between going down a dark alley at night or walking along a lit sidewalk: practical intelligence would encourage the route that seems more likely to ensure a safe journey home. Creative intelligenceis the ability to adapt to new situations and create new ideas. Someone who can create a tower out of raw spaghetti and marshmallows likely has high creative intelligence.

Gardner’s Theory of Multiple Intelligences

Howard Gardner argued that it is evolutionarily beneficial for people to have different talents, skills, and intelligences. Gardner’s (1983, 1999) Theory of Multiple Intelligences states that there are eight specific types of intelligence and people possess all of them in varying degrees.

Table 8.1 Howard Gardner’s eight specific intelligences

Some have argued that these “intelligences” seem more like “abilities” or “talents” rather than real intelligence. There is no clear conclusion about how many intelligences there are. Are sense of humor, artistic skills, dramatic skills, and so forth also separate intelligences? Furthermore, the cognitive-based intelligences (linguistic, logical-mathematical, and spatial) are highly correlated, which shows continued evidence for the singular intelligence factor “g” (Visser et al., 2006).

The idea of multiple intelligences changed the field of education by encouraging personalized learning (Cuevas, 2015). While the Multiple Intelligences Theory is not explicitly about “learning styles,” or how students may best learn information, Gardner encouraged teachers to make learning as specific as possible to each student (Allcock & Hulme, 2010; Cuevas, 2015; Gardner, 1983). For instance, to teach math problems to students who have particularly good kinesthetic intelligence, a teacher might encourage them to move their bodies or hands according to the numbers.

Despite their popularity in educational settings, though, there is little evidence that teaching to a specific learning style improves understanding of material (Allcock & Hulme, 2010; Pashler et al., 2009). In fact, learning styles may harm students who think they can only learn or study in one particular way (Zwaagstra, 2022). While it’s likely that students have a preference of how they would like to learn, catering to those preferences doesn’t ensure that they will learn better (Rogowsky et al., 2020).

Video 8.2 Theories of Intelligence reviews a few of the different theoretical views of intelligence.